An aircraft engine , often referred to as an aero engine , is the power component of an aircraft propulsion system . Aircraft using power components are referred to as powered flight . Most aircraft engines are either piston engines or gas turbines , although a few have been rocket powered and in recent years many small UAVs have used electric motors .
92-525: The Rolls-Royce Vulture was a British aero engine developed shortly before World War II that was designed and built by Rolls-Royce Limited . The Vulture used the unusual " X-24 " configuration, whereby four cylinder blocks derived from the Rolls-Royce Peregrine were joined by a common crankshaft supported by a single crankcase . The engine was originally designed to produce around 1,750 horsepower (1,300 kW ) but problems with
184-443: A gas turbine engine offered. Thus was born the idea to mate a turbine engine to a traditional propeller. Because gas turbines optimally spin at high speed, a turboprop features a gearbox to lower the speed of the shaft so that the propeller tips don't reach supersonic speeds. Often the turbines that drive the propeller are separate from the rest of the rotating components so that they can rotate at their own best speed (referred to as
276-717: A $ 5.6 billion deal to upgrade its Patriot missile-defence shield, and in 2017, Saudi Arabia signed business deals worth billions of dollars with multiple American companies, including Raytheon. In February 2020, Raytheon completed the first radar antenna array for the US Army's new missile defense radar, known as the Lower Tier Air and Missile Defense Sensor (LTAMDS), to replace the service's Patriot air and missile defense system sensor. In 1929, William Boeing 's Boeing Airplane & Transport Corporation teamed up with Frederick Rentschler 's Pratt & Whitney to form
368-618: A better efficiency. A hybrid system as emergency back-up and for added power in take-off is offered for sale by Axter Aerospace, Madrid, Spain. Small multicopter UAVs are almost always powered by electric motors. Reaction engines generate the thrust to propel an aircraft by ejecting the exhaust gases at high velocity from the engine, the resultant reaction of forces driving the aircraft forwards. The most common reaction propulsion engines flown are turbojets, turbofans and rockets. Other types such as pulsejets , ramjets , scramjets and pulse detonation engines have also flown. In jet engines
460-419: A combustion section where fuel is added and ignited, one or more turbines that extract power from the expanding exhaust gases to drive the compressor, and an exhaust nozzle that accelerates the exhaust gases out the back of the engine to create thrust. When turbojets were introduced, the top speed of fighter aircraft equipped with them was at least 100 miles per hour faster than competing piston-driven aircraft. In
552-564: A common crankshaft. The vast majority of V engines are water-cooled. The V design provides a higher power-to-weight ratio than an inline engine, while still providing a small frontal area. Perhaps the most famous example of this design is the legendary Rolls-Royce Merlin engine, a 27-litre (1649 in ) 60° V12 engine used in, among others, the Spitfires that played a major role in the Battle of Britain . A horizontally opposed engine, also called
644-701: A component of the Dow Jones Industrial Average on March 4, 1939, when United Aircraft and AT&T were added to replace Nash Motors and International Business Machines . The company and its successors remained a component of the Dow Jones Industrial Average through August 2020. It was announced that starting August 31, 2020, Raytheon Technologies would be substituted in the Dow Jones Industrial Average by Honeywell International . During World War II, United Aircraft ranked sixth among United States corporations in
736-470: A consequence the reliability of the Vulture when it entered service was very poor. Apart from delivering significantly less than the designed power, the Vulture suffered from frequent failures of the connecting rod big end bearings, which was found to be caused by a breakdown in lubrication, and also from heat dissipation problems. Rolls-Royce were initially confident that they could solve the problems, but
828-477: A contract to build 3DELRR, a next-generation long-range radar system, for the US Air Force worth an estimated $ 1 billion. The contract award involved the construction of next-generation radar that can track aircraft, missiles, and remotely piloted aircraft. It was immediately protested by Raytheon's competitors. After re-evaluating the bids following the protests, the US Air Force decided to delay awarding
920-490: A cooling system into the air duct of a hydrogen jet engine permits greater fuel injection at high speed and obviates the need for the duct to be made of refractory or actively cooled materials. This greatly improves the thrust/weight ratio of the engine at high speed. It is thought that this design of engine could permit sufficient performance for antipodal flight at Mach 5, or even permit a single stage to orbit vehicle to be practical. The hybrid air-breathing SABRE rocket engine
1012-440: A cylinder on the other side. Opposed, air-cooled four- and six-cylinder piston engines are by far the most common engines used in small general aviation aircraft requiring up to 400 horsepower (300 kW) per engine. Aircraft that require more than 400 horsepower (300 kW) per engine tend to be powered by turbine engines . An H configuration engine is essentially a pair of horizontally opposed engines placed together, with
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#17327766425671104-408: A flat or boxer engine, has two banks of cylinders on opposite sides of a centrally located crankcase. The engine is either air-cooled or liquid-cooled, but air-cooled versions predominate. Opposed engines are mounted with the crankshaft horizontal in airplanes , but may be mounted with the crankshaft vertical in helicopters . Due to the cylinder layout, reciprocating forces tend to cancel, resulting in
1196-572: A fraction of the cost of traditional engines. Such conversions first took place in the early 1970s; and as of 10 December 2006 the National Transportation Safety Board has only seven reports of incidents involving aircraft with Mazda engines, and none of these is of a failure due to design or manufacturing flaws. The most common combustion cycle for aero engines is the four-stroke with spark ignition. Two-stroke spark ignition has also been used for small engines, while
1288-407: A free-turbine engine). A turboprop is very efficient when operated within the realm of cruise speeds it was designed for, which is typically 200 to 400 mph (320 to 640 km/h). Turboshaft engines are used primarily for helicopters and auxiliary power units . A turboshaft engine is similar to a turboprop in principle, but in a turboprop the propeller is supported by the engine and the engine
1380-456: A handful of types are still in production. The last airliner that used turbojets was the Concorde , whose Mach 2 airspeed permitted the engine to be highly efficient. A turbofan engine is much the same as a turbojet, but with an enlarged fan at the front that provides thrust in much the same way as a ducted propeller , resulting in improved fuel efficiency . Though the fan creates thrust like
1472-470: A move to support UTC's Fire & Security unit . In September 2011, UTC acquired an $ 18.4 billion deal (including $ 1.9 billion in net debt assumed) for aircraft components maker Goodrich Corporation . In July 2012, United Technologies acquired Goodrich and merged it with Hamilton Sundstrand , forming UTC Aerospace Systems . In November 2018, UTC acquired Rockwell Collins for $ 23 billion ($ 30 billion including Rockwell Collins' net debt). As part of
1564-569: A peak pressure of 30 MPa (300 bar). Although engine weight increases by 30%, aircraft fuel consumption is reduced by 15%. Sponsored by the European Commission under Framework 7 project LEMCOTEC , Bauhaus Luftfahrt, MTU Aero Engines and GKN Aerospace presented the concept in 2015, raising the overall engine pressure ratio to over 100 for a 15.2% fuel burn reduction compared to 2025 engines. On multi-engine aircraft, engine positions are numbered from left to right from
1656-478: A piston-engine with two 10 piston banks without a high-pressure turbine, increasing efficiency with non-stationary isochoric - isobaric combustion for higher peak pressures and temperatures. The 11,200 lb (49.7 kN) engine could power a 50-seat regional jet . Its cruise TSFC would be 11.5 g/kN/s (0.406 lb/lbf/hr) for an overall engine efficiency of 48.2%, for a burner temperature of 1,700 K (1,430 °C), an overall pressure ratio of 38 and
1748-424: A propeller, the surrounding duct frees it from many of the restrictions that limit propeller performance. This operation is a more efficient way to provide thrust than simply using the jet nozzle alone, and turbofans are more efficient than propellers in the transsonic range of aircraft speeds and can operate in the supersonic realm. A turbofan typically has extra turbine stages to turn the fan. Turbofans were among
1840-415: A provider of security operations centers, managed security service solutions and cybersecurity professional services, for $ 62 million. In January 2016, Raytheon|Websense acquired the firewall provider Stonesoft from Intel Security for an undisclosed amount and renamed itself to Forcepoint. In July 2016, Poland's Defence Minister Antoni Macierewicz planned to sign a letter of intent with Raytheon for
1932-425: A search for replacement fuels for general aviation aircraft a priority for pilots’ organizations. Turbine engines and aircraft diesel engines burn various grades of jet fuel . Jet fuel is a relatively less volatile petroleum derivative based on kerosene , but certified to strict aviation standards, with additional additives. Model aircraft typically use nitro engines (also known as "glow engines" due to
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#17327766425672024-567: A sharp increase in interim sales and profits. On June 7, 2022, the company announced plans to move its global headquarters to Arlington, Virginia . The move was completed in July. In January 2023, Raytheon Technologies announced it would combine its missiles and defense division and intelligence and space division into a single business unit, effective July 1. The reorganization created three divisions at Raytheon Technologies: Collins Aerospace, Pratt & Whitney, and Raytheon. The reorganization
2116-404: A smooth running engine. Opposed-type engines have high power-to-weight ratios because they have a comparatively small, lightweight crankcase. In addition, the compact cylinder arrangement reduces the engine's frontal area and allows a streamlined installation that minimizes aerodynamic drag. These engines always have an even number of cylinders, since a cylinder on one side of the crankcase "opposes"
2208-600: A type of radio-receiver power supply that plugged into the power grid in place of large batteries . This made it possible to convert household alternating current to direct current for radios and thus eliminate the need for expensive, short-lived batteries. In 1925, the company changed its name to Raytheon Manufacturing Company and began marketing its rectifier under the Raytheon brand name, with commercial success. In 1928, Raytheon merged with Q.R.S. Company, an American manufacturer of electron tubes and switches, to form
2300-623: Is a large military contractor, getting much of its revenue from the U.S. government. The company was formed in 2020 by a merger of equals between the aerospace subsidiaries of United Technologies Corporation (UTC) and the Raytheon Company . Before the merger, UTC spun off its non-aerospace subsidiaries Otis Elevator Company and Carrier Corporation . UTC is the nominal survivor of the merger but it changed its name to Raytheon Technologies and moved its headquarters to Waltham, Massachusetts. Former UTC CEO and chairman Gregory J. Hayes
2392-533: Is a pre-cooled engine under development. At the April 2018 ILA Berlin Air Show , Munich -based research institute de:Bauhaus Luftfahrt presented a high-efficiency composite cycle engine for 2050, combining a geared turbofan with a piston engine core. The 2.87 m diameter, 16-blade fan gives a 33.7 ultra-high bypass ratio , driven by a geared low-pressure turbine but the high-pressure compressor drive comes from
2484-449: Is a twin-spool engine, allowing only two different speeds for the turbines. Pulsejets are mechanically simple devices that—in a repeating cycle—draw air through a no-return valve at the front of the engine into a combustion chamber and ignite it. The combustion forces the exhaust gases out the back of the engine. It produces power as a series of pulses rather than as a steady output, hence the name. The only application of this type of engine
2576-490: Is above and behind. In the Cessna 337 Skymaster , a push-pull twin-engine airplane, engine No. 1 is the one at the front of the fuselage, while engine No. 2 is aft of the cabin. Aircraft reciprocating (piston) engines are typically designed to run on aviation gasoline . Avgas has a higher octane rating than automotive gasoline to allow higher compression ratios , power output, and efficiency at higher altitudes. Currently
2668-646: Is an American multinational aerospace and defense conglomerate headquartered in Arlington, Virginia . It is one of the largest aerospace and defense manufacturers in the world by revenue and market capitalization, as well as one of the largest providers of intelligence services. In 2023, the company's seat in Forbes Global 2000 was 79. RTX manufactures aircraft engines , avionics , aerostructures , cybersecurity solutions, guided missiles , air defense systems , satellites , and drones . The company
2760-453: Is bolted to the airframe : in a turboshaft, the engine does not provide any direct physical support to the helicopter's rotors. The rotor is connected to a transmission which is bolted to the airframe, and the turboshaft engine drives the transmission. The distinction is seen by some as slim, as in some cases aircraft companies make both turboprop and turboshaft engines based on the same design. A number of electrically powered aircraft, such as
2852-469: Is chairman and CEO of the combined company, which changed its name to RTX in July 2023. The company has three subsidiaries: Collins Aerospace , Pratt & Whitney , and Raytheon (formerly Raytheon Intelligence & Space and Raytheon Missiles & Defense ). The Raytheon Company was founded in 1922 in Cambridge, Massachusetts , by Laurence K. Marshall, Vannevar Bush , and Charles G. Smith as
Rolls-Royce Vulture - Misplaced Pages Continue
2944-400: Is located above the cylinders, it is called an inverted inline engine: this allows the propeller to be mounted high up to increase ground clearance, enabling shorter landing gear. The disadvantages of an inline engine include a poor power-to-weight ratio , because the crankcase and crankshaft are long and thus heavy. An in-line engine may be either air-cooled or liquid-cooled, but liquid-cooling
3036-720: Is more common because it is difficult to get enough air-flow to cool the rear cylinders directly. Inline engines were common in early aircraft; one was used in the Wright Flyer , the aircraft that made the first controlled powered flight. However, the inherent disadvantages of the design soon became apparent, and the inline design was abandoned, becoming a rarity in modern aviation. For other configurations of aviation inline engine, such as X-engines , U-engines , H-engines , etc., see Inline engine (aeronautics) . Cylinders in this engine are arranged in two in-line banks, typically tilted 60–90 degrees apart from each other and driving
3128-400: Is not limited to engines with a single row of cylinders. This is typically to differentiate them from radial engines . A straight engine typically has an even number of cylinders, but there are instances of three- and five-cylinder engines. The greatest advantage of an inline engine is that it allows the aircraft to be designed with a low frontal area to minimize drag. If the engine crankshaft
3220-430: Is of lesser concern, rocket engines can be useful because they produce very large amounts of thrust and weigh very little. A rocket turbine engine is a combination of two types of propulsion engines: a liquid-propellant rocket and a turbine jet engine. Its power-to-weight ratio is a little higher than a regular jet engine, and works at higher altitudes. For very high supersonic/low hypersonic flight speeds, inserting
3312-496: The American Appliance Company . Its focus, which was originally on new refrigeration technology, soon shifted to electronics . The company's first product was a gaseous ( helium ) rectifier that was based on Charles Smith's earlier astronomical research of the star Zeta Puppis . The electron tube was christened with the name Raytheon ("light of/from the gods" ) and was used in a battery eliminator ,
3404-527: The CK722 , priced for and marketed to hobbyists. Under the direction of Thomas L. Phillips in 1965, it acquired Amana Refrigeration , Inc., a manufacturer of refrigerators and air conditioners . Using the Amana brand name and its distribution channels, Raytheon began selling the first countertop household microwave oven in 1967 and became a dominant manufacturer in the microwave oven business. In 1991, during
3496-776: The Hawker Typhoon , which was powered by the Napier Sabre . The cancellation caused the abandonment of the Vulture-engined version of the Vickers Warwick bomber. The only aircraft type designed for the Vulture to go into production was the twin-engined Avro Manchester . When the engine reliability problems became clear, the Avro team persuaded the Air Ministry that switching to a four-Merlin version of
3588-701: The Persian Gulf War , Raytheon's Patriot missile received great international exposure. It was credited for downing Iraqi Scud missiles . The exposure resulted in a substantial increase in sales for the company outside the United States. By 2006, Raytheon reported $ 283.9 million in global revenues for its Patriot missile system. In an effort to establish leadership in the defense electronics business, Raytheon purchased in quick succession Dallas-based E-Systems (1995); Chrysler Corporation 's defense electronics and aircraft-modification businesses, and
3680-591: The Pratt & Whitney JT9D for the Boeing 747 . In 1974, Harry Jack Gray left Litton Industries to become the CEO of United Aircraft. He pursued a strategy of growth and diversification, changing the parent corporation's name to United Technologies Corporation (UTC) in 1975 to reflect the intent to diversify into numerous high tech fields beyond aerospace. (The change became official on May 1, 1975.) The diversification
3772-527: The QinetiQ Zephyr , have been designed since the 1960s. Some are used as military drones . In France in late 2007, a conventional light aircraft powered by an 18 kW electric motor using lithium polymer batteries was flown, covering more than 50 kilometers (31 mi), the first electric airplane to receive a certificate of airworthiness . On 18 May 2020, the Pipistrel E-811 was
Rolls-Royce Vulture - Misplaced Pages Continue
3864-416: The Rolls-Royce Peregrine , were fairly standard designs, with two cylinder banks arranged in a V form and with a displacement of 21 litres (1,300 cu in). The Vulture was, in effect, two Peregrines joined by a new crankcase turning a new crankshaft, producing an X engine configuration with a displacement of 42 litres (2,600 cu in). The Vulture used cylinders of the same bore and stroke as
3956-684: The Rutan Quickie . The single-rotor engine was put into a Chevvron motor glider and into the Schleicher ASH motor-gliders. After the demise of MidWest, all rights were sold to Diamond of Austria, who have since developed a MkII version of the engine. As a cost-effective alternative to certified aircraft engines some Wankel engines, removed from automobiles and converted to aviation use, have been fitted in homebuilt experimental aircraft . Mazda units with outputs ranging from 100 horsepower (75 kW) to 300 horsepower (220 kW) can be
4048-522: The United Aircraft and Transport Corporation , a large, vertically integrated , amalgamated firm, uniting business interests in all aspects of aviation —a combination of aircraft engine and airframe manufacturing and airline business, to serve all aviation markets, both civil aviation (cargo, passenger, private , air mail ) and military aviation . After the Air Mail scandal of 1934,
4140-424: The gyroscopic effects of the heavy rotating engine produced handling problems in aircraft and the engines also consumed large amounts of oil since they used total loss lubrication, the oil being mixed with the fuel and ejected with the exhaust gases. Castor oil was used for lubrication, since it is not soluble in petrol, and the resultant fumes were nauseating to the pilots. Engine designers had always been aware of
4232-424: The oxygen necessary for fuel combustion comes from the air, while rockets carry an oxidizer (usually oxygen in some form) as part of the fuel load, permitting their use in space. A turbojet is a type of gas turbine engine that was originally developed for military fighters during World War II . A turbojet is the simplest of all aircraft gas turbines. It consists of a compressor to draw air in and compress it,
4324-485: The 3DELRR EMD contract until 2017 and was to issue an amended solicitation at the end of July 2016. In 2017 the Air Force again awarded the contract to Raytheon. In May 2015, Raytheon acquired cybersecurity firm Websense, Inc. from Vista Equity Partners for $ 1.9 billion and combined it with RCP, formerly part of its IIS segment to form Raytheon|Websense. In October 2015, Raytheon|Websense acquired Foreground Security,
4416-817: The Clerget 14F Diesel radial engine (1939) has the same power to weight ratio as a gasoline radial. Improvements in Diesel technology in automobiles (leading to much better power-weight ratios), the Diesel's much better fuel efficiency and the high relative taxation of AVGAS compared to Jet A1 in Europe have all seen a revival of interest in the use of diesels for aircraft. Thielert Aircraft Engines converted Mercedes Diesel automotive engines, certified them for aircraft use, and became an OEM provider to Diamond Aviation for their light twin. Financial problems have plagued Thielert, so Diamond's affiliate — Austro Engine — developed
4508-701: The Manchester, which had been in development as a contingency, was preferable to retooling Avro factories to make the Handley Page Halifax . The resulting aircraft was initially called the Manchester Mark III and then subsequently renamed Avro Lancaster , going on to great success as the RAF's leading heavy bomber. Data from Lumsden and Gunston. Comparable engines Related lists Aircraft engine In commercial aviation
4600-623: The New York Stock Exchange under the ticker RTX. On July 28, 2020, the company announced cutting of over 8,000 jobs in its commercial aviation division due to travel slowdown induced by the global COVID-19 pandemic . In December 2020, the Board of Directors authorized a $ 5 billion repurchase of common stock. In 2022, during the Russian invasion of Ukraine , major arms manufacturers, including Raytheon Technologies, reported
4692-605: The Peregrine, but the cylinder spacing was increased to accommodate a longer crankshaft, necessary for extra main bearings and wider crankpins . The engine suffered from an abbreviated development period because Rolls-Royce suspended Vulture development in 1940 during the Battle of Britain to concentrate on the Merlin, which powered the RAF's two main fighters, the Hawker Hurricane and Supermarine Spitfire , and as
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#17327766425674784-716: The U.S. government concluded that such large holding companies as United Aircraft and Transport were anti-competitive, and new antitrust laws were passed forbidding airframe or engine manufacturers from having interests in airlines. United Aircraft Corporation was formed in 1934 from United Aircraft and Transport's manufacturing interests east of the Mississippi River (Pratt & Whitney, Sikorsky, Vought, and Hamilton Standard Propeller Company), headquartered in Hartford with Frederick Rentschler , founder of Pratt & Whitney, as president. United Aircraft became
4876-488: The Vulture design meant that the engines were derated to around 1,450 to 1,550 hp in service by limiting the maximum rpm . Although several new aircraft designs had been planned to use the Vulture, work on the engine's design ended in 1941 as Rolls-Royce concentrated on their more successful Merlin design. Another 24-cylinder engine, the Napier Sabre , proved more successful after a lengthy development period. The supercharged Rolls-Royce Kestrel and its derivative,
4968-574: The Wankel engine has been used in motor gliders where the compactness, light weight, and smoothness are crucially important. The now-defunct Staverton-based firm MidWest designed and produced single- and twin-rotor aero engines, the MidWest AE series . These engines were developed from the motor in the Norton Classic motorcycle . The twin-rotor version was fitted into ARV Super2s and
5060-403: The company was responsible for about 80 percent of all magnetrons manufactured. During the war, Raytheon also pioneered the production of shipboard radar systems, particularly for submarine detection. Raytheon ranked 71st among United States corporations in the value of World War II military production contracts. In 1945, Raytheon's Percy Spencer invented the microwave oven by discovering that
5152-543: The company's much smaller Merlin was already nearing the same power level as the Vulture's original specification, in part because of its accelerated development in 1940, and so production of the Vulture was discontinued after only 538 had been built. The Vulture had been intended to power the Hawker Tornado interceptor but with the cancellation of Vulture development, Hawker abandoned the Tornado and concentrated on
5244-500: The compression-ignition diesel engine is seldom used. Starting in the 1930s attempts were made to produce a practical aircraft diesel engine . In general, Diesel engines are more reliable and much better suited to running for long periods of time at medium power settings. The lightweight alloys of the 1930s were not up to the task of handling the much higher compression ratios of diesel engines, so they generally had poor power-to-weight ratios and were uncommon for that reason, although
5336-593: The cylinders arranged evenly around the crankshaft, although some early engines, sometimes called semi-radials or fan configuration engines, had an uneven arrangement. The best known engine of this type is the Anzani engine, which was fitted to the Bleriot XI used for the first flight across the English Channel in 1909. This arrangement had the drawback of needing a heavy counterbalance for the crankshaft, but
5428-486: The cylinders in a circle around the crankcase, as in a radial engine, (see above), but the crankshaft is fixed to the airframe and the propeller is fixed to the engine case, so that the crankcase and cylinders rotate. The advantage of this arrangement is that a satisfactory flow of cooling air is maintained even at low airspeeds, retaining the weight advantage and simplicity of a conventional air-cooled engine without one of their major drawbacks. The first practical rotary engine
5520-592: The deal, Pratt and Whitney and the newly-formed Collins Aerospace remained under United Technologies, while Otis Elevator and UTC Climate, Controls & Security (doing business as Carrier ) were spun off as two independent companies. The spin off was completed in March 2020. In June 2019, United Technologies announced the intention to merge with the Raytheon Company. The combined company, valued at more than $ 100 billion after planned spinoffs, would be
5612-436: The defense unit of Texas Instruments , Defense Systems & Electronics Group (1997). The businesses were purchased for $ 2.3 billion and $ 2.95 billion, respectively. Also in 1997, Raytheon acquired the aerospace and defense business of Hughes Aircraft Company from Hughes Electronics Corporation , a subsidiary of General Motors , which included a number of product lines previously purchased by Hughes Electronics, including
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#17327766425675704-581: The engine core is the bypass ratio. Low-bypass engines are preferred for military applications such as fighters due to high thrust-to-weight ratio, while high-bypass engines are preferred for civil use for good fuel efficiency and low noise. High-bypass turbofans are usually most efficient when the aircraft is traveling at 500 to 550 miles per hour (800 to 890 kilometres per hour), the cruise speed of most large airliners. Low-bypass turbofans can reach supersonic speeds, though normally only when fitted with afterburners . The term advanced technology engine refers to
5796-438: The engine works by having a coiled pipe in the combustion chamber that superheats the fuel (propane) before being injected into the air-fuel inlet. In the combustion chamber, the fuel/air mixture ignites and burns, creating thrust as it leaves through the exhaust pipe. Induction and compression of the fuel/air mixture is done both by the pressure of propane as it is injected, along with the sound waves created by combustion acting on
5888-415: The engine's heat-radiating surfaces to the air and tends to cancel reciprocating forces, radials tend to cool evenly and run smoothly. The lower cylinders, which are under the crankcase, may collect oil when the engine has been stopped for an extended period. If this oil is not cleared from the cylinders prior to starting the engine, serious damage due to hydrostatic lock may occur. Most radial engines have
5980-849: The fire and security business by purchasing Chubb Security . In 2004, UTC acquired the Schweizer Aircraft Corporation which planned to operate as a wholly owned subsidiary under their Sikorsky Aircraft division. In 2005, UTC further pursued its stake in the fire and security business by purchasing Kidde . Also in 2005, UTC acquired Boeing's Rocketdyne division, which was merged into the Pratt & Whitney business unit and renamed Pratt & Whitney Rocketdyne (later sold to Aerojet and merged into Aerojet Rocketdyne ). In November 2008, UTC's Carrier Corporation acquired NORESCO, an energy service company . In 2010, UTC conducted its largest acquisition to date, General Electric 's security equipment business for US$ 1.8 billion,
6072-606: The first electric aircraft engine to be awarded a type certificate by EASA for use in general aviation . The E-811 powers the Pipistrel Velis Electro . Limited experiments with solar electric propulsion have been performed, notably the manned Solar Challenger and Solar Impulse and the unmanned NASA Pathfinder aircraft. Many big companies, such as Siemens, are developing high performance electric engines for aircraft use, also, SAE shows new developments in elements as pure Copper core electric motors with
6164-399: The first engines to use multiple spools —concentric shafts that are free to rotate at their own speed—to let the engine react more quickly to changing power requirements. Turbofans are coarsely split into low-bypass and high-bypass categories. Bypass air flows through the fan, but around the jet core, not mixing with fuel and burning. The ratio of this air to the amount of air flowing through
6256-718: The former General Dynamics missile business (Pomona facility), the defense portion of Delco Electronics (Delco Systems Operations), and Magnavox Electronic Systems . Raytheon also divested itself of several nondefense businesses in the 1990s, including Amana Refrigeration and Seismograph Service Ltd (sold to Schlumberger - Geco-Prakla ). In November 2007, Raytheon purchased robotics company Sarcos , and in October 2009, Raytheon acquired BBN Technologies . In December 2010, Applied Signal Technology agreed to be acquired by Raytheon for $ 490 million. In October 2014, Raytheon beat rivals Lockheed Martin and Northrop Grumman for
6348-497: The intake stacks. It was intended as a power plant for personal helicopters and compact aircraft such as Microlights. A few aircraft have used rocket engines for main thrust or attitude control, notably the Bell X-1 and North American X-15 . Rocket engines are not used for most aircraft as the energy and propellant efficiency is very poor, but have been employed for short bursts of speed and takeoff. Where fuel/propellant efficiency
6440-562: The magnetron could rapidly heat food. In 1947, the company demonstrated the Radarange microwave oven for commercial use. After the war, Raytheon developed the first guidance system for a missile that could intercept a flying target. In 1948, Raytheon began to manufacture guided missiles , including the SAM-N-2 Lark , and eventually the air-to-air AIM-7 Sparrow , and the ground-to-air MIM-23 Hawk missiles. In 1959, Raytheon acquired
6532-478: The major Western manufacturers of turbofan engines are Pratt & Whitney (a subsidiary of Raytheon Technologies ), General Electric , Rolls-Royce , and CFM International (a joint venture of Safran Aircraft Engines and General Electric). Russian manufacturers include the United Engine Corporation , Aviadvigatel and Klimov . Aeroengine Corporation of China was formed in 2016 with
6624-430: The many limitations of the rotary engine so when the static style engines became more reliable and gave better specific weights and fuel consumption, the days of the rotary engine were numbered. The Wankel is a type of rotary engine. The Wankel engine is about one half the weight and size of a traditional four-stroke cycle piston engine of equal power output, and much lower in complexity. In an aircraft application,
6716-425: The marine electronics company Apelco Applied Electronics, which significantly increased its strength in commercial marine navigation and radio gear, and changed its name to Raytheon Company. During the post-war years, Raytheon also made generally low- to medium-powered radio and television transmitters and related equipment for the commercial market. In the 1950s, Raytheon began manufacturing transistors , including
6808-462: The merger of several smaller companies. The largest manufacturer of turboprop engines for general aviation is Pratt & Whitney. General Electric announced in 2015 entrance into the market. In this section, for clarity, the term "inline engine" refers only to engines with a single row of cylinders, as used in automotive language, but in aviation terms, the phrase "inline engine" also covers V-type and opposed engines (as described below), and
6900-433: The modern generation of jet engines. The principle is that a turbine engine will function more efficiently if the various sets of turbines can revolve at their individual optimum speeds, instead of at the same speed. The true advanced technology engine has a triple spool, meaning that instead of having a single drive shaft, there are three, in order that the three sets of blades may revolve at different speeds. An interim state
6992-463: The most common Avgas is 100LL. This refers to the octane rating (100 octane) and the lead content (LL = low lead, relative to the historic levels of lead in pre-regulation Avgas). Refineries blend Avgas with tetraethyllead (TEL) to achieve these high octane ratings, a practice that governments no longer permit for gasoline intended for road vehicles. The shrinking supply of TEL and the possibility of environmental legislation banning its use have made
7084-404: The new AE300 turbodiesel , also based on a Mercedes engine. Competing new Diesel engines may bring fuel efficiency and lead-free emissions to small aircraft, representing the biggest change in light aircraft engines in decades. While military fighters require very high speeds, many civil airplanes do not. Yet, civil aircraft designers wanted to benefit from the high power and low maintenance that
7176-431: The point of view of the pilot looking forward, so for example on a four-engine aircraft such as the Boeing 747 , engine No. 1 is on the left side, farthest from the fuselage, while engine No. 3 is on the right side nearest to the fuselage. In the case of the twin-engine English Electric Lightning , which has two fuselage-mounted jet engines one above the other, engine No. 1 is below and to the front of engine No. 2, which
7268-432: The power-to-weight ratio is very important, making the Wankel engine a good choice. Because the engine is typically constructed with an aluminium housing and a steel rotor, and aluminium expands more than steel when heated, a Wankel engine does not seize when overheated, unlike a piston engine. This is an important safety factor for aeronautical use. Considerable development of these designs started after World War II , but at
7360-465: The successor of the same name, Raytheon Manufacturing Company. By the 1930s, it had already grown to become one of the world's largest vacuum tube manufacturing companies. In 1933 it diversified by acquiring Acme-Delta Company, a producer of transformers , power equipment, and electronic auto parts . During World War II, Raytheon mass-manufactured magnetron tubes for use in microwave radar sets and then complete radar systems . At war's end in 1945,
7452-439: The time the aircraft industry favored the use of turbine engines. It was believed that turbojet or turboprop engines could power all aircraft, from the largest to smallest designs. The Wankel engine did not find many applications in aircraft, but was used by Mazda in a popular line of sports cars . The French company Citroën had developed Wankel powered RE-2 [ fr ] helicopter in 1970's. In modern times
7544-414: The two crankshafts geared together. This type of engine has one or more rows of cylinders arranged around a centrally located crankcase . Each row generally has an odd number of cylinders to produce smooth operation. A radial engine has only one crank throw per row and a relatively small crankcase, resulting in a favorable power-to-weight ratio . Because the cylinder arrangement exposes a large amount of
7636-423: The use of a glow plug ) powered by glow fuel , a mixture of methanol , nitromethane , and lubricant. Electrically powered model airplanes and helicopters are also commercially available. Small multicopter UAVs are almost always powered by electricity, but larger gasoline-powered designs are under development. Raytheon Technologies RTX Corporation , formerly Raytheon Technologies Corporation ,
7728-409: The value of wartime production contracts. At the close of the war, United Aircraft entered the emerging markets for jet engines and helicopters , via Pratt & Whitney and Sikorsky, respectively. In the 1950s, United Aircraft began developing jet engines, including the Pratt & Whitney J57 , the most powerful jet engine on the market for some years. In the 1960s, Pratt & Whitney produced
7820-645: The weight of losses incurred by the commercial M&A side of the business. Although M&A activity was not new to United Aircraft, the M&;A activity of the 1970s and 1980s was higher-stakes and arguably unfocused. Rather than aviation being the central theme of UTC businesses, high tech (of any type) was the new theme. Some Wall Street watchers questioned the true value of M&A at almost any price, seemingly for its own sake. In 1999, UTC acquired Sundstrand Corporation and merged it into UTC's Hamilton Standard unit to form Hamilton Sundstrand . In 2003, UTC entered
7912-528: The world's second-largest aerospace-and-defense company by sales behind Boeing. Although UTC was the legal survivor, the merged company took the name Raytheon Technologies and based its headquarters at Raytheon's former campus in Waltham, Massachusetts , rather than UTC's former base in Farmington, Connecticut . The merger was completed in April 2020. Raytheon Technologies began trading at $ 51 per share, on
8004-399: The years after the war, the drawbacks of the turbojet gradually became apparent. Below about Mach 2, turbojets are very fuel inefficient and create tremendous amounts of noise. Early designs also respond very slowly to power changes, a fact that killed many experienced pilots when they attempted the transition to jets. These drawbacks eventually led to the downfall of the pure turbojet, and only
8096-506: Was partially to balance civilian business against any overreliance on military business. UTC became a mergers and acquisitions (M&A)–focused organization, with various forced takeovers of unwilling smaller corporations. The next year (1976), UTC forcibly acquired Otis Elevator . In 1979, Carrier Refrigeration was acquired; At one point the military portion of UTC's business, whose sensitivity to "excess profits" and boom/bust demand drove UTC to diversify away from it, actually carried
8188-753: Was preceded by the rebranding to RTX in June 2023. In July 2023, Raytheon Technologies Corporation changed its name to RTX Corporation. RTX's supply of weapons to Israel led to protests against the company during the 2023 Israel–Hamas war . On December 14, 2023, for example, protestors blocked the entrance to an RTX facility in Arizona. In early 2024, 15 people were arrested after blocking access to RTX and BAE Systems facilities in Louisville, Kentucky in protest against supplying weapons to Israel. In December 2023, RTX announced that CEO Greg Hayes would step down
8280-572: Was the Gnome Omega designed by the Seguin brothers and first flown in 1909. Its relative reliability and good power to weight ratio changed aviation dramatically. Before the first World War most speed records were gained using Gnome-engined aircraft, and in the early years of the war rotary engines were dominant in aircraft types for which speed and agility were paramount. To increase power, engines with two rows of cylinders were built. However,
8372-479: Was the German unmanned V1 flying bomb of World War II . Though the same engines were also used experimentally for ersatz fighter aircraft, the extremely loud noise generated by the engines caused mechanical damage to the airframe that was sufficient to make the idea unworkable. The Gluhareff Pressure Jet (or tip jet) is a type of jet engine that, like a valveless pulsejet, has no moving parts. Having no moving parts,
8464-487: Was used to avoid the spark plugs oiling up. In military aircraft designs, the large frontal area of the engine acted as an extra layer of armor for the pilot. Also air-cooled engines, without vulnerable radiators, are slightly less prone to battle damage, and on occasion would continue running even with one or more cylinders shot away. However, the large frontal area also resulted in an aircraft with an aerodynamically inefficient increased frontal area. Rotary engines have
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